Arm E: NVP (200 mg bid) in combination with NRTIs. Acceptable NRTIs and any fixed combination of these medications include: zidovudine (ZDV), lamivudine, didanosine, stavudine (d4T), zalcitabine, and abacavir; concurrent therapy using ZDV and d4T is not allowed. ARV therapy is not provided by this study. One dose of DMPA is provided to all patients at entry (Day 0) and an optional dose of DMPA will be available at the final visit (Week 12) for those who are interested in continuing with DMPA outside of the protocol and who do not experience adverse events from the first DMPA injection. Patients in Arms B, C, D, and E have intensive pharmacokinetic sampling done at entry and at Week 4 to measure ARV levels. All patients have blood tests at Weeks 2, 4, 6, 8, 10, and 12 to measure levels of DMPA and progesterone. In addition, tests to monitor HIV-1 RNA levels, CD4 and CD8 counts, hematology, blood chemistries, and liver function are performed periodically.